Catocala ultronia has distinctive forewing markings: a dark bar along the inner margin; extensive grayish-white scaling above this bar from the basal area to the outer margin; a darker apex; relatively small reniform and subreniform spots.
This moth proved to be quite skittish and it was hard to get a good picture with or without wings spread. Tim put some wine in the bait and that seemed to slow the moth a bit.
Catocala ultronia, August 17, 2004, Peterborough, Ontario, courtesy of Tim Dyson copyright.
Henry (left-click on the frog) to find more